Carton with self-sealing end closures



United States Patent O 2,896,836 CARTON WITH SELF-SEALING END CLOSURES Frank D. Bergstein, Cincinnati, Ohio, assignor to Bergstein Packaging Trust Application December 1'4, 1956, Serial No. 628,365 3 Claims. (Cl. 229-37) My invention relates to paperboard cartons and more particularly to self-sealing cartons which are provided with overlapping closure aps carrying coatings of pressure sensitive adhesive or similar adhesive material which will form a seal upon contact of one adhesively coated flap with another adhesively coated flap.

In recent years there has developed an increasing demand for self-sealing cartons of the type which may be shipped in fiat-folded form with a self-sealing adhesive already applied to the closure aps so that all the user has to do is to erect the carton body and press the closure flaps one over the other to complete the sealing operation without the application of a liquid adhesive at the time of assembly or without having to reactivate an adhesive pre-applied to the closure flaps. While selfsealing cartons are commercially available, their manufacture has presented numerous diiiiculties which have necessitated special handling of the carton blanks and the use of special equipment. In particular, the application of the self-sealing adhesive to the closure aps necessitates some kind of a drying operation before the knocked-down structures can be stacked for storage and shipment. This means that the blanks must be maintained separated from each other until the necessary' drying has been obtained. Similarly, even after the adhesive has been dried so as to be non-tacky, care must be taken to see that the at-folded cartons are so stacked that the adhesively coated flaps of one carton do not contact the adhesively coated flaps of the adjacent carton. As will be evident, such special handling not only reduces the speed at which the cartons can be fabricated but at the same time it materially increases their cost.

It is, therefore, a principal object of my invention to provide a carton structure having self-sealing end Clo-- sures which can be fabricated on conventional folding and gluing equipment at high speeds and the flat-folded cartons immediately stacked for storage and shipment'with- .out first drying or partially drying the adhesive coatings.

A further object of my invention is the provision a carton structure of the character described in which the flat-folded structures may be stacked one upon the other Without theadhesive areas of one carton coming into contact with any portion of the next adjacent carton structure. Y

Still a further object of my invention is the provision y of a self-sealing carton structure embodying a novel protective frame as an integral part of the end closures thereof, the frame serving to protect the adhesive coatings and prevent them from coming into contact with any?.

portion of the next vadjacent structure when the structures are stacked one upon the other.

Still a further object of my invention is the formation of an extremely simple carton blank having the desired frame forming construction and yet requiring a minimum of board in its formation.

The foregoing, together with other objects of my invention which will appear hereinafter or which will be apparent to the skilled worker in the art upon reading 2,896,836 Patented July 28, 1959 Mice .folded condition.

Figure 3 is a plan view similar to Figure 2 but with the frame forming portions of the end closure in folded condition. Y

Figure 4 is an enlarged fragmentary perspective View illustrating one end of the flat-folded blank.

Figure 5 is a sectional view taken along the line 5-5 of Figure 4.

Figure 6 is an end elevational view illustrating a plurality of the blanks stacked one upon the other.

Figure 7 is a schematic elevational view illustrating the manner in which the blanks would be collected from a high speed folding and gluing machine.

Figure 8 is a fragmentary perspective view illustrating the manner in Which the end closures of the erected carton are sealed. Y i

' Figure 9 is a fragmentary side elevational View illustrating the end closure of Figure 8 in sealed condition.

Referring first to Figure l of the drawings, I have therein illustrated a carton blank in accordance with my invention. It will be understood that the blank will be formed from suitable paperboard or iiberboard cut and scored to provide bodywalls 1, 2, 3 and 4 in articulation in the order named, and a glue flap 5 articulated to the free side edge of the body wall 4. In the embodiment illustrated, the carton body is provided with top closure flaps 6, 7, 8 and 9; and similarly, the bottom closure is composed of ap members 10, 11, 12, and 13. Preferably the end closure flaps articulated to the larger pair of body walls, i.e., the bodywalls 2 and 4, will be full width closure flaps having awidth substantially equal to the width of the opposed pair of body walls 1 vand 3. Thus, the end closure flaps 7, 9, 11 and 13 are full width flaps. The remaining aps, namely the flaps 6, 8, 10 and 12 are of reduced width and have a depth substantially one-half that of the full width flaps. In addition, the full width aps 9 and 13 have apertures 14 and 15 which define frame forming members 16 and17 occupying the outermost half of each flap, the frame members being connected to the base portions 18 and 19 of the aps by means of lines of fold 20 which, in the preferred embodiment, are formed in-prolongation of the innermost edge of the cutout portions 14 and15.

In fabricating hat-folded box structures from the blank just described, lthe blank will be rst moved in the direction of the arrow A (Figure 2), and the body Walls 1 and 4 infolded along their `lines of articulation to the body walls 2 and 3, respectively, thereby bringing the parts to the position illustrated in Figure 2 in which the free edge of body Wall 1 is juxtaposed to the glue flap 5. Prior to the infolding of the parts adhesive 21 will have been applied either to the glue flap 5 or to the portion of body wall 1 contacted thereby. VA longitudinal 'seam is thus effected and the blank is brought to a fiat-folded. tubular condition. Thereafter, the adhesive is applied to vthe closure flaps. f

3 seen in Figure 3, the adhesive substance will be applied to the outermost portions of fthe full Width flaps 7 and 11, such adhesive lareas being @indicated at 22andg23. arly, adhesive Yareas 24 fand 25 .will be applied to the innermost or base portions 18 and 19 of -iaps 9 and 13,. As will be 'evident from Figures 3 and 4, .fthe frame members 16 and 17 are infolded along the score :lines 2 0 sonas itofoverlie .their respective -base iportions :i8 :and '19. The frame members thus serve as a protective fra-me for the `adhesive areas 24 andLZS; 'and to ethis end, the dimensions of the adhesive areas will be such that ,they will :t

within the contines fof the frame members .16 and 17.

11a-connection with :the :frame members, it may zbe observed that they may be infolded While the blank :is `movzing `inthe :direction .of arrow A (Figure 2,) lby using'suitable kicker means itozfold them inwardly. Alternatively, where za iight angle folding zand gluing machine iis ernployed, the blank may be moved in the direction rof the larrow B (Figure "3) and :the frame .members folded inwardly by suitable sweeps :or the like. As to theappli- "cation -of the 4adhesive :areas 24 and 25, they ymay be :applied either prior vto jor lSubsequent Yto -the -infolding of the frame members. ,fIt will be apparent, however, that the adhesive areas '22 Yand 23 will :be applied subsequent tothe yinfolding lof zthe frame members.

With the parts in the position illustrated :in :Figures 4 and 5., it will be:r eadily appar ent 'that the blanks :may be immediately stacked one upon the other without the adhesive areas lof one blank coming into :contact -withany portion of lthe next :adjacent blank. Thus, the adhesive vareas22 and 2S are Iprotected vfrom an overlying blank by the thickness of ftheendfiaps c6, 10 :and 9, l1-3 -and the Vadditionalthickness of the folded frame-members 16 and 17. .As will be'clearly-apparent from Figure 5 'the frame members, suchias the :member 17, form vprotective spacers forthe .adhesive areas24 and 25,*the adhesiveareas lying lwithin the connesfofthefframe. Thus aplurality :ofat- 4folded blanks 26,27, 28 and 29 ,(:Figur e: 6) 'maylbe stacked yoneupon the1otherfwhile-the adhesive .isstill wetuwithout 'fear ofthe parts sticking-together. While Figure 6 -illusvtrates a plurality A,of flat-folded -blanks as they would be stacked one iuponthe other,Figure 7'illustrates their position as they would ibe ifed from-,a high ispe'edfolding fand :gluing machine, the blanks fbeing juxtaposed side-by-side lin;inclined relation, :as yat 30, and -fedfforwardly jforsubsequent stacking xbylbelt and rollericonveyorrneans Sindi be understood that the frame members may take other catedgenerallyat 31. In lthis connection, itmay .beob- -srer-ved that :the stacked carton Vblanksmay :be collected and Vpacked in shipping cases for 'istoragefor shipment before the adhesive is completely dry.

Figures 7 .and l8 illustratethezmanner in'which the end closures are sealed. YAs :seen therein, the :bodylof the carton is brought to ferected condition, pas vby applying inwardlyfdirected ,pressure .against the edgesof fthe flatfolded blank, whereuponl theniirstfoldedclosure 'flaps' 6 and 8 are yinfolded followed yby the infolding of the :flap 9. -In connection with :the infolding of fap f9 it 'will be v`noted that-the frame Vrnember 116 is infolded yso vas .tolie substantially coplanar Vwith l the 'base portion 118, Athereby exposing .the adhesive areas 24. Thereafter .the outer- Ymost full width flap 7 is infolded andthe adhesivearea 22y juxtaposed to theeXpos'ed adhesive area .24, vthereby leiecting al seal between 'the'parts The completed and 'sealed end closure is illustrated iri`Figre 9. It` will ,be

understood thatthe' bottom closure will'beefe'cted in'like *mannen Modifications may be made in my invention w'itho'ut'vz departing from theespiritlof itandthe-particular form of cartonherein illustrated-'is but'an exemplary embodiment fof-my invention. Itfwill -be apparent-that the dimensions koffthe carton=body lwalls-:as lwell as the dimensions-ofthe l-end closure flaps may kbe 4varied Without :departing ffrom,y the :spirit of thelinvention. Similarly; whilefIzhave illusftrated the 1 frame members 2in fthe form:of an .enclosure surrounding the adhesive areas to be protected, it is to forms. For example, the frame could simply bracket the glue areas rather than surround them completely, the essential requisite being that the frame members shield and protect the adhesive areas from contact with a juxtaposed surface. The frame :principle of my invention is applicable to other types of box structures wherein the orientation of the *frame 'members ito the blank Ais other than that snfwically'illustrated, the essential Vrequisite here being thatdie framemembers :be hingedly Connected tothe .blank in such a way that they Imay be folded to bracket or otherwise protect the adhesive areas. `While I have described my invention -as it .applies to the protection of the adhesive areas in a self-sealing type of carton, it will be readily apparent that the frames may be utilized with any type of structure wherein the problem of protecting -a wet or tacky glue area isy encountered.

'Having thus described myinvention in .an Vexemplary embodiment, what I desire to .secure and protect by yLet- -ters Patent -isz l. `In -a self-sealing -carton structure, .a rectangular body composed of .-a xplurality of body walls .in sideby-side articulation, said rcaiton body being flat-folded -so-fas to ,have two adjacent body -walls foverlying and juxtaposed to two other adjacent body walls'thereurider, .,a rst closure flap hingedly connected :to an end edge of one A-of said underlying #body walls, a second closure flap ar- -;ingouter,part-being'folded Ialong said-hinge line to overflie said inner part l:and having :a .substantial 4portion thereof -cut away to expose the underlying Allportion of said inner ;part,'said'rvst closure 4iiap being longer than ithe finnerfpart-offsaidsecond closureqap so as to lhave raaportion thereof .projecting beyond ysaid folded second closure flapfand a. c oating:of gadhesivezonsaid iirst flap confined to the projecting portion thereof and on Athe inner part .of gsaidqsecond ilap -coniined to the portion `thereof f exposed l,by :said 'frame part.

The structure .claimed in `claim 1 wherein additional end closure naps :are hingedly connected to Ythe corresponding 5end edges of the Vremaining `carton body walls, and wherein the .uppermost of said additional v`closurefilarzs hasalength .no fgreater than theleilgth 0f the inner part of saidsecond Vclosure vap.

iln'carton structures adapted to be stacked one upon the rother in V,flat folded condition lwhile -areas `of .fad-

.-hesive.app1ed'-ztheretn are Vin :tacky condition, .each of said carton structures comprising a rectangular :tubular body composed :offra .plurality vvof v body -walls connected together in v; sjiid e-b y.-si-de articulation, @said carton .body

being at-folded sofas arto .have :two adjacent body walls .overlying and juxtaposed to ftwoeother adjacent body walls 'thereunder,.each of fsaid body :walls havingfclosure flaps Aprojecting outwardlyfxfrom .its i opposite.A ends, afrst foverlying closureiflap at eachfend of .thecarton tbody being divided along a hinge line parallelingthe end ting inner-part'gand ra-f-rame iforming outer part, said ap ,at. each end. of theca'rton. body having a length f substantially equal 7to ,the length of .the .base vpart A,of `the adjacent ,iirstcvcrl-ying closure flap, vat least. oneA lof y.the underlying closure aps at eachendofthe Acartornbeing longer thanlthefinncrfipart of Ythe ysaidadjacent -iirst :overlying flap fso eas :tofbave gagportion thcreofz-proiect- 1 fing :outwardly beyond the l[folded edge of :saidnadiacent rst overlying flap, and a tacky adhesive confined to the said projecting portions of said underlying flaps and to the portions of the inner ap parts of said rst named overlying flaps exposed through said frame parts, whereby when a plurality of said flat-folding carton structures are stacked one upon the other, the said frame parts will serve as spacers effective to prevent contact between the adhesive areas on one carton and the undersurface of the next adjacent carton in the stack.

References Cited in the tile of this patent UNITED STATES PATENTS 682,063 Haberstroh Sept. 3, 1901 Koster Jan. 9, 1934- Swift Ian. 5, 1937 Lindley Oct. 15, 1940 Grecco Oct. 10, 1944 Glasser Apr. 15, 1952 Henderson Mar. 15, 1955 FOREIGN PATENTS Great Britain Dec. 6, 1950 

